Hypoxia continues to be a significant source of peril in military aviation. Over three dozen hypoxia-related incidents were reported in the past decade with three resulting in fatalities (Clark & Megown, 2005;Ostrander, 2008). Previous work has addressed loss of consciousness resulting from extreme levels of hypoxia (Carlyle, 1963); however, most mishaps are related to moderate hypoxia exposure. More work is required to establish the cognitive effects of moderate hypoxia and the time required, post-exposure, to fully recover. The present study examined the effect of a ten minute exposure to an air mixture equivalent to 20,000 ft on two-choice reaction time. Carryover effects were assessed over a ten minute recovery period. Hypoxia exposure resulted in significant delays in two-choice reaction time. Significant carry-over effects continued to be detected throughout the recovery period. This information is essential to military aviation, where high levels of cognitive performance are required after moderate hypoxia exposure.

Fatigue is the most frequently cited physiological factor contributing to the occurrence of US Naval Aviation Class A flight mishaps. Accordingly, the Naval Safety Center (NSC) has identified the need for a quickly-administered individualized fatigue assessment tool to determine a pilot or aircrew member's readiness to fly. The Naval Aerospace Medical Research Laboratory conducted validation research on Flight Fit-a series of computer administered cognitive tasks sensitive to fatigue, and PMI FIT 2000-a physiological test of oculometric properties linked to fatigue, for their potential to serve as individualized fatigue detection tools. Performance on both assessments was observed in concordance with performance on a suite of industry standard fatigue-sensitive measures (e.g., the Psychomotor Vigilance Test) at regular intervals over 25 hours of continual wakefulness in naval aviators. Results indicate significant group and individual differences related to fatigue for several aspects of both measures, and suggest that with appropriate adjustments, both Flight Fit and PMI FIT 2000 could serve as valid real-time readiness-to-fly assessment tools in Naval Aviation squadrons. Follow-on studies to determine the exact nature of these adjustments and usability of the tools in their current form are discussed.

Results of the current study strongly suggest that intranasal scopolamine is efficacious for the treatment of motion sickness in susceptible individuals with no significant cognitive or sedative effects. Intranasal delivery offers a promising alternative for use in dynamic operational environments without cognitive detriment or increased side effects.

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Executive SummaryMotion sickness often leads to decrements in operational performance for personnel working in dynamic environments. Previous research examining pharmacological solutions for motion sickness have reported that dextroamphetamine (d-amphetamine) imparts significant protection against provocative motion, when compared to other standard countermeasures such as antihistamines, without conferring drowsiness or significant side effects. The military currently prescribes Dexedrine ® to assist with fatigue deterrence during periods of high operational tempo and/or extended flight operations. If the reported anti-motion sicknesses properties of d-amphetamine can be confirmed, the military could utilize a single medication for motion sickness and fatigue prevention. The purpose of this study was to determine the efficacy and side effect profile of this potential motion sickness countermeasure for us e in military environments. It was hypothesized that subjects in the oral d-amphetamine (10 mg, d-amphet) condition will tolerate more head movements than subjects in the placebo condition, without exhibiting performance decrements or significant side effects. Thirty-six aviation candidates, 31 male and 5 female, were recruited and randomized to one of two treatment groups (10 mg, damphet or placebo) and then exposed to passive Coriolis cross-coupling. Medication efficacy was determined by number of head movements tolerated between groups. Cognitive and medication side-effect profiles for both groups were derived from performance on the ANAM ® Readiness Evaluation System (ARES ® ) cognitive battery, measurements of near-focus visual accommodation (VA), scores on the Karolinska Sleepiness Scale (KSS), and motion sickness questionnaires. Analyses failed to discern significant differences in the number of head movements tolerated between groups or treatment effects over time on the ARES ® cognitive battery, VA, or KSS, p > 0.05. A negative linear relationship was found between Motion Sickness Susceptibility Questionnaire-Short (MSSQ-Short) scores and number of head movements (r = -.24, p < .05). In summary, d-amphetamine did not provide significant motion sickness protection when compared to placebo and no significant impacts on performance or medication-induced side effects were observed. 3 Introduction Definition and HistoryMotion sickness is the body's normal physiological response to unrecognized movement elicited by various forms of real or apparent motion. The primary signs and symptoms are nausea, vomiting, drowsiness, pallor, increased salivation, flushing/warmth, cold sweating, headache, and dizziness. The earliest writings on motion sickness and its ill effects were recorded by the ancient Greeks whose word "naus", from which the word nausea originated, means ship. Seafaring militaries have been afflicted by the detrimental effects of motion sickness for as long as countries have set out to explore and conquer other lands. In the reviews by Bard (1948), Chinn & Smith (1955), Reason andBrand (1975), andTyl...